1. Field of the Invention
The present invention relates to a process of storing photographic images in an image pickup apparatus.
2. Related Background Art
Conventionally, there are commercially available image pickup apparatus such as digital cameras and others for recording and reproducing still images picked up by an image pickup element such as a CCD or the like, using a memory card having a solid state memory device as a recording medium. These image pickup apparatus are often configured to perform the following processes: a photographing process of taking output data from the image pickup element once into a buffer memory, a development compression process of subjecting the data to image processing and compression processing and again storing the resultant data in the buffer memory, and thereafter a writing process of writing the data into a removable recording medium.
For these image pickup apparatus, a method of processing during continuous shooting was proposed as a method of first continuously carrying out photographing processes as long as the buffer memory had a vacant storage area, and thereafter carrying out the development compression process in the number of picked-up pictures. (Cf. Japanese Patent Application Laid-Open No. 7-99629.)
Another method commonly applied was a method of carrying out the photographing process of picking up one picture and immediately thereafter carrying out the development compression process for the picked-up picture. Timing charts during execution of processing in these methods are presented in FIG. 15 and FIG. 16, respectively.
However, the method of first continuously carrying out the photographing process up to the end of the space in the buffer memory and thereafter carrying out the development compression process in the number of picked-up pictures as described above permits higher continuous shooting speed in continuous shooting than the method of alternately carrying out the photographing process and the development compression process, but has the problem that, because the capacity of data outputted after the photographing process is greater than that obtained after the compression process of the data, the number of pictures that could be continuously stored in the buffer memory become smaller, to decrease the number of pictures that could be continuously picked-up during continuous shooting.
On the other hand, the method of alternately carrying out the photographing process and the development compression process has the problem that the continuously shooting speed is slow. Further, the both methods take a long total processing time, because the photographing process and the development compression process are sequentially carried out.